Search

The phenomenon of sudden drought after pluvial (or heavy pluvial after drought) is known as the Dry–Wet Abrupt Alternation (DWAA). This kind of disaster has been evaluated globally based on various DWAA indices. However, few validations have been performed to compare the various DWAA indices. Given that directly validating the identified DWAA events remains difficult because of the limited historical records of DWAA events, in this study, we developed a simple weighting analysis method to cross‐validate the detected DWAA events using three widely‐used indices. The weighting analysis method can be used to estimate the effectiveness of the DWAA indices by calculating the ratio of the synchronous DWAA events (the DWAA events could be synchronously detected by different indices) to the total number of the detected DWAA events. Results suggest that the standard weighted average of precipitation (SWAP) index has better performance for detecting DWAA events in the Pearl River Basin (PRB) compared to other indices. The soil moisture synchronization, meteorological concentration and real DWAA records further testify that the SWAP is more capable of detecting the DWAA events in the PRB. Based on the validation, the SWAP‐derived DWAA events show that both dry–wet (D–W) events and wet–dry events are severe in the upstream sub‐basins in the PRB, while D–W events are more frequent in the downstream PRB. Our study provides a simple but effective method to validate the detected DWAA. The finding underscores the need to validate DWAA detection generated from multiple indicators before further research, and it could help develop adaptation strategies to improve resilience to combined extremes under changing climate. [ABSTRACT FROM AUTHOR]

The phenomenon of sudden drought after pluvial (or heavy pluvial after drought) is known as the Dry–Wet Abrupt Alternation (DWAA). This kind of disaster has been evaluated globally based on various DWAA indices. However, few validations have been performed to compare the various DWAA indices. Given that directly validating the identified DWAA events remains difficult because of the limited historical records of DWAA events, in this study, we developed a simple weighting analysis method to cross‐validate the detected DWAA events using three widely‐used indices. The weighting analysis method can be used to estimate the effectiveness of the DWAA indices by calculating the ratio of the synchronous DWAA events (the DWAA events could be synchronously detected by different indices) to the total number of the detected DWAA events. Results suggest that the standard weighted average of precipitation (SWAP) index has better performance for detecting DWAA events in the Pearl River Basin (PRB) compared to other indices. The soil moisture synchronization, meteorological concentration and real DWAA records further testify that the SWAP is more capable of detecting the DWAA events in the PRB. Based on the validation, the SWAP‐derived DWAA events show that both dry–wet (D–W) events and wet–dry events are severe in the upstream sub‐basins in the PRB, while D–W events are more frequent in the downstream PRB. Our study provides a simple but effective method to validate the detected DWAA. The finding underscores the need to validate DWAA detection generated from multiple indicators before further research, and it could help develop adaptation strategies to improve resilience to combined extremes under changing climate. [ABSTRACT FROM AUTHOR]

Input ground motions have significant impacts on the uncertainty of structural responses in time-history analysis. In this study, records were selected and scaled for the evaluation of mean structural responses according to the target spectrum. The Newmark-Hall spectrum is closely related to seismic response of short, medium and long-period structures, so it was taken as the target spectrum here. The nonlinear time-history analyses of 9-story and 20-story steel moment-resisting frame structures were carried out as examples. They represent medium and long-period buildings, respectively. Three target spectra with risk of 50%, 10% and 2% probabilities for exceedance in 50 years were calculated by the average Newmark-Hall spectrum method for three ground motion sets developed in the SAC Steel Project. The predicted structural mean responses of these Newmark-Hall spectra were compared with those calculated by the average spectral acceleration method for the same record set. It is found that both methods have similar accuracy for estimating the structural mean response. However, the method proposed herein is more effective in reducing the variability of the structural responses. Also, the proposed method is more advantageous for the time-history analysis of long-period structures or structures with more severe nonlinear responses under strong seismic excitations. [ABSTRACT FROM AUTHOR]

• The 1.5 °C, 2 °C, 3 °C, and 4 °C warming scenarios are established by CMIP6 experiments. • The 1.5 °C and 2 °C warming targets avert an expansion of unprecedented drought. • Unprecedented drought tends to emerge earlier in most of the sub-tropics. • The time of emergence of unprecedented drought is modulated by precipitation change. In the context of anthropogenic global warming, unprecedented drought is expected to emerge over some regions where drought conditions exceed the variation range of the natural state. However, it is still unclear how the 1.5 °C and 2 °C warming targets proposed by the Paris Agreement will delay or even prevent the emergence of unprecedented drought. To illustrate the benefits of the two warming targets for mitigating drought conditions, this study investigated the time of emergence (TOE) of unprecedented meteorological drought as indicated by the Standardized Precipitation Evapotranspiration Index (SPEI) using the Coupled Model Intercomparison Project Phase 6 (CMIP6) model ensembles forced by 4 Shared Socioeconomic Pathways (SSP1–2.6, SSP2–4.5, SSP3–7.0, and SSP5–8.5). In particular, the pattern of TOE is explored for 4 pseudo warming scenarios under which global mean surface temperature (GMST) increases by 1.5 °C, 2 °C, 3 °C, and 4 °C above pre-industrial levels, respectively. The results suggested that: (1) Under the 1.5 °C and 2 °C warming scenarios, unprecedented meteorological drought is anticipated to emerge over southern Africa, Arabian Peninsula, central Asia, Mongolia, southwestern South America, and western and eastern Australia. (2) Under the 3 °C and 4 °C warming scenarios, unprecedented meteorological drought will expand to western North America, the Amazon, and the Mediterranean. (3) The comparisons with the exposure under the 3 °C and 4 °C warming scenarios show that the aspirational 1.5 °C and 2 °C Paris Agreement warming targets can prevent at least 0.6 × 107 km2 of land area, 1.4 × 108 people, and 0.6 × 106 km2 of cropland area from suffering the emergence of unprecedented meteorological drought. [Display omitted] [ABSTRACT FROM AUTHOR]

• We presented a method to rapidly and in-situ extract the Seebeck coefficient of thermopile IR sensors over a wide temperature range (300–600 K). • The effectiveness of this method is evaluated by a thermopile IR sensor. The maximum relative error between the results obtained from this method and specialized instrument (NETZSCH SBA 458 Nemesis) does not exceed 9%. The Seebeck coefficient of thermopile infrared (IR) sensors is a crucial parameter. The ability to rapidly and in-situ extract the Seebeck coefficient across a wide temperature range is advantageous for assessing the impact of temperature on sensor's performance. In this study, specific sets of current excitations are used, the exothermic and endothermic temperature changes caused by Peltier effect are offset, and the Seebeck coefficient of sensor over a wide temperature range (300–600 K) is extracted from Joule heat by measuring the resistance of sensor. The effectiveness of this method is evaluated by a thermopile IR sensor. The maximum relative error between the results obtained from this method and specialized instrument does not exceed 9 %. [ABSTRACT FROM AUTHOR]

• The drought projection uncertainty in SMILEs mainly arises from internal variability. • Model uncertainty is the major uncertainty source of drought projection in CMIP6. • Model (scenario) uncertainty dominates the near-term (long-term) drought projection. • The reducible model uncertainty is mainly distributed in tropical regions. Reliable projection of future drought conditions is critical for informing adaptation in response to future climate change. However, the uncertainty associated with drought projection impedes the precise estimation of drought risk and consequently efficient adaptation strategy. To better understand the role of uncertainty in drought projection, this study distinguished the total uncertainty of drought projection into scenario uncertainty, model uncertainty, and internal variability uncertainty by variance analysis using realizations from the Single Model Initial-condition Large Ensembles (SMILEs) and the Coupled Model Intercomparison Project Phase 6 (CMIP6). The results showed that SMILEs differ from CMIP6 mainly in the magnitude of internal variability and model uncertainty. The contribution of internal variability to total drought projection uncertainty in SMILEs (31–56 %) is greater than that in CMIP6 (9–21 %), while model uncertainty of SMILEs (36–41 %) is nearly half that of CMIP6 (67–76 %). The estimation of total uncertainty in drought projection is comparable between SMILEs and CMIP6, indicating that total uncertainty attains a minimum in the mid-21st century (the 2060 s for SMILEs and 2050 s for CMIP6). In addition, SMILEs and CMIP6 consistently show that model uncertainty is dominant in tropical regions, and scenario uncertainty is the main uncertainty contributor in western North America, eastern South America, the Mediterranean, and southern Australia. [ABSTRACT FROM AUTHOR]

Defective pixels always exist in an uncooled infrared focal plane array (IR FPA), and have a significant impact on image quality. To fundamentally reduce defective pixels and improve IR FPA’s reliability, failure analysis (FA) is critically needed. In this work, a self-test (ST) method is proposed to detect the structural failures of uncooled IR FPA. Based on the lumped thermal parameters of a pixel, a structural failures model is presented, and an electrical circuit is designed. The insufficient released, normal released, over released and contaminated IR FPAs are measured. The measured results show that their lumped thermal parameters have a clear differentiation, which not only experimentally verifies the validity of this method, but also shows that it is an effective method for nondestructive analysis of structural failures. [ABSTRACT FROM AUTHOR]

Host-side flash caching emerges as an effective solution for improving the performance of virtual machines (VMs) in cloud computing environment. However, for VMs with the commonly used Copy-on-Write (COW) virtual disks, flash caching in fact has negative impacts since it brings lots of unnecessary cache writes, hurting both the VM performance and the flash endurance. This paper presents COWCache, a COW-aware caching solution that addresses this problem by co-designing flash caching with COW-based virtual disks. First, COWCache designs a new architecture that bridges the semantic gap between flash caching and virtual disk management for realizing the VMs' real data locality. Second, it separately manages COW metadata with fine-grained caching and journaling to improve the metadata caching efficiency. Third, it provides a novel decoupled Copy-on-Write mechanism, which decouples the amplified data requests from the critical I/O path and only admits the data with real VM locality into flash cache. COWCache also introduces a new data structure, the virtual cache map, to mitigate the memory footprint overhead for indexing the cached data in flash. Evaluations show that COWCache improves the application performance by up to 122.7% and reduces the flash cache writes by up to 78.5% compared to traditional flash caching solutions. [ABSTRACT FROM AUTHOR]

Tea contains high quantities and diverse types of triterpenoids, particularly in the form of saponins. However, little is yet known about the molecular basis of triterpenoid biosynthesis in tea plant. Here we report on isolation and functional analysis of squalene synthase (SQS) gene from tea plant (Camellia sinensis var. sinensis), which controls the biosynthesis of triterpenoids precursor. First, a full-length cDNA of squalene synthase, designated CsSQS , was isolated from tea plant. The protein is highly homologous to SQSs from other plants. Using CsSQS-reporter assays, CsSQS was demonstrated to be endoplasmic reticulum membrane-bound. The coding region of CsSQS excluding transmemberane sequence was expressed in Escherichia coli. Recombinant CsSQS catalyzed the formation of squalene using farnesyl-pyrophosphate (FPP) as substrate with NADPH and Mg2+. In tea plant leaves, CsSQS expression was significantly induced by both herbivore and mechanical damages. Consistent with the stronger induction of CsSQS expression by mechanical damage than herbivory, tea plants injured mechanically released squalene as a volatile compound, which however was not detected from herbivore-damaged tea plants. Furthermore, it was found that the flowers of another tea plant cultivar Camellia sinensis var. assamica contain higher concentrations of squalene than the cultivar sinensis , indicating variations among tea plant varieties. With the identification and molecular characterization of squalene synthase in tea plant, next, we can ask the questions about the roles of squalene as a volatile product as well as a precursor for triterpenoids, which may promote product development from diverse tea materials and mining of excellent tea germplasm resources. • SQS gene in tea plant was isolated and the enzymatic activities of the encoded protein were identified. • Volatile squalene can be detected in flowers of C. sinensis var. assamica. • SQS release can be dramatically induced by mechanical damage in tea plant. [ABSTRACT FROM AUTHOR]

Global warming is anticipated to largely impact drought dynamics. Therefore, a comprehensive projection of global drought under various future warming levels is critical for water resources management. This study investigated the changes in the severity, intensity, area, and duration of droughts at 1.5 °C, 2 °C, 3 °C, and 4 °C of global warming above pre-industrial levels based on the latest simulations under climate change scenarios from the Coupled Model Intercomparison Project Phase 6 (CMIP6). The Standardized Precipitation Evapotranspiration Index (SPEI) at 3-month time scale was adopted to characterize seasonal droughts. The results show that: 1) Global land is projected to experience a significant nonlinear increasing trend of drought severity, intensity, areal extent, and duration during the 21st century, and drought characteristics have the highest growth rate under the 3 °C warming scenario, followed by the 4 °C, 2 °C, and 1.5 °C warming scenarios. 2) Under the 1.5 °C and 2 °C warming levels, drought characteristics in most land areas change slightly compared to the baseline period of 1995–2014. 3) Hotspots defined as robust increases in drought severity appear in the 3 °C and 4 °C warming world, including northern South America, Europe, northern and southern Africa, western and central Asia, and central Australia, whereas eastern North America and the Russian Arctic exhibit substantial reduction in drought severity under different global warming levels. 4) Global warming is projected to change the timing of droughts, leading to more frequent summer droughts in Europe. Overall, the findings of this study provide a scientific basis for articulating future global drought adaption and highlight the need for mitigation measures to limit greenhouse gas emissions to achieve the 2 °C target of the Paris Agreement. [Display omitted] • A three-dimensional clustering algorithm is used to analyze drought characteristics. • Global warming is projected to accelerate the growth rate of drought characteristics. • Drought characteristics change slightly in the 1.5 °C and 2 °C warming periods. • More severe drought events will occur at global warming levels of 3 °C and 4 °C. • Europe will suffer more frequent summer droughts as global warming continues. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • A simple sensor structure with self-heating effect of diode is proposed. • The sensor size is reduced by removing dedicated heating structure and optimizing the fabrication process. • High performance is obtained by employing series diodes. • The proposed sensor has high sensitivity and low power consumption. Abstract Diode based micro-Pirani vacuum sensors attract considerable attention because they do not require special materials and are compatible with complementary metal oxide semiconductors (CMOS). However, their complex heating structure makes it difficult to reduce the sensor size. This paper reports a novel compact micro-Pirani vacuum sensor based on series diodes. The self-heating effect of the series diodes helps simplify the structural design by avoiding a dedicated heating structure. Moreover, the small size of the series diodes ensures high temperature coefficient. The proposed design reduces the sensor size without sacrificing the performance. In fact, simulation results indicate that the series diodes help enhance the device performance. A sensor was fabricated by a CMOS compatible process. The sensor size was reduced significantly to 35 μm × 35 μm. The sensor is sensitive to the vacuum pressure range from 10−1 Pa to 104 Pa when driven by a constant current as small as 10 μA, and the power consumption is low at 50 μW. [ABSTRACT FROM AUTHOR]

Highlights • Investigate the responses of runoff coefficient to precipitation seasonality. • Investigate influence of precipitation seasonality on the lower bound in Budyko space. • Provide a higher infimum of Budyko curves in comparison of the horizontal axis. Abstract As a boundary condition, the lower bound is a prerequisite for constructing the Budyko framework. However, the traditional lower bound i.e., the horizontal axis is an analytical boundary without considering realistic conditions. In fact, under real-word condition, the lower bound of Budyko curves, representing the maximum value of water yield, should be located above the horizontal axis due to complicated constraints from basin characteristics, especially the precipitation seasonality, a key driver of runoff yield and a dominant factor in constructing Budyko framework. Thus, this study focused on exploring the reasonable location of the lower bound by adequately analyzing potential influence of precipitation seasonality. To do that, multiple hydrological simulations in basins under different climate and topography conditions were developed based on various precipitation scenarios constructed by using Markov chain with full range of precipitation seasonality. To fully understand the influence from precipitation seasonality on the lower bound, the water-energy supply and the basin characteristics were fixed by aridity index and hydrological model parameters, respectively. The results reveal a positive correlation between runoff coefficient and precipitation seasonality with an obvious higher location above the horizontal axis, indicating the horizontal axis is imprecise to describe the upper bound of runoff yield under real-word condition. Furthermore, a potential location of the lower bound above the horizontal axis in Budyko space was found based on runoff yield mechanism under real basin condition, representing a more appropriate boundary condition of Budyko framework. [ABSTRACT FROM AUTHOR]

Abstract Low stress silicon (Si)-rich silicon nitride (SiN x) films are usually used as membranes of microcapsules for transmission electron microscopy (TEM). Their relatively high atomic number has a negative impact on resolution, which is a key factor that affects imaging performance. To improve resolution, reducing Si content in films is an effective approach. However, the non-Si-rich SiN x films have large tensile stress and are ease to crack. In this study, ion implantation is utilized to adjust the stress of nearly stoichiometric (NS) SiN x films. The effects of ion implantation and thermal annealing on film properties are carefully analyzed. It is found that the NS SiN x films implanted with nitrogen (N) and annealed at low anneal temperature have both low atomic number and low stress, and their properties are very close to low stress Si-rich SiN x films. Moreover, a simple microcapsule is fabricated using the low atomic number SiN x films, and performs a TEM observation of water-soluble polypeptides growth. Polypeptides much smaller than 100 nm in size are observed. [ABSTRACT FROM AUTHOR]

An approach for improving sidewall roughness of high-aspect-ratio trench is developed. This method relies on the aspect ratio dependent scalloping attenuation (ARDSA) effect in Bosch process, employs reactive ion etching (RIE) process to avoid the rippled sidewall at the top of the trench, while retains Bosch process with increasing trench depth. As both the RIE and Bosch processes are recognized production techniques, this method is easy to implement. Compared with standard Bosch process, the maximum root mean square (RMS) roughness of the sidewall is brought down from 15.1 nm to 6.89 nm. [ABSTRACT FROM AUTHOR]

Microbial terpene synthase-like ( MTPSL ) genes are a type of terpene synthase genes only recently identified in plants. In contrast to typical plant terpene synthase genes, which are ubiquitous in land plants, MTPSL genes appear to occur only in nonseed plants. Our knowledge of catalytic functions of MTPSLs is very limited. Here we report biochemical characterization of the enzymes encoded by MTPSL genes from two closely related species of hornworts, Anthoceros punctatus and Anthoceros agrestis . Seven full-length MTPSL genes were identified in A. punctatus ( ApMTPSL1 - 7 ) based on the analysis of its genome sequence. Using homology-based cloning, the apparent orthologs for six of the ApMTPSL genes, except ApMTPSL2 , were cloned from A. agrestis . They were designated AaMTPSL1, 3–7 . The coding sequences for each of the 13 Anthoceros MTPSL genes were cloned into a protein expression vector. Escherichia coli -expressed recombinant MTPSLs from hornworts were assayed for terpene synthase activities. Six ApMTPSLs and five AaMTPSLs, except for ApMTPSL5 and AaMTPSL5, showed catalytic activities with one or more isoprenyl diphosphate substrates. All functional MTPSLs exhibited sesquiterpene synthase activities. In contrast, only ApMTPSL7 and AaMTPSL7 showed monoterpene synthase activity and only ApMTPSL2, ApMTPSL6 and AaMTPSL6 showed diterpene synthase activity. Most MTPSLs from Anthoceros contain uncanonical aspartate-rich motif in the form of either ‘DDxxxD’ or ‘DDxxx’. Homology-based structural modeling analysis of ApMTPSL1 and ApMTPSL7, which contain ‘DDxxxD’ and ‘DDxxx’ motif, respectively, showed that ‘DDxxxD’ and ‘DDxxx’ motifs are localized in the similar positions as the canonical ‘DDxxD’ motif in known terpene synthases. To further understand the role of individual aspartate residues in the motifs, ApMTPSL1 and ApMTPSL7 were selected as two representatives for site-directed mutagenesis studies. No activities were detected when any of the conserved aspartic acid was mutated into alanine. This study provides new information about the catalytic functions of MTPSLs and the functionality of their uncanonical aspartate-rich motifs, and builds a knowledge base for studying the biological importance of MTPSL genes and their terpene products in nonseed plants. [ABSTRACT FROM AUTHOR]

Estimating continental water availability is of great importance for water resources management, in terms of maintaining ecosystem integrity and sustaining society development. To more accurately quantify the predictability of water availability, on the basis of univariate probabilistic Budyko framework, a bivariate probabilistic Budyko approach was developed using copula-based joint distribution model for considering the dependence between parameter ω of Wang-Tang’s equation and the Normalized Difference Vegetation Index (NDVI), and was applied globally. The results indicate the predictive performance in global water availability is conditional on the climatic condition. In comparison with simple univariate distribution, the bivariate one produces the lower interquartile range under the same global dataset, especially in the regions with higher NDVI values, highlighting the importance of developing the joint distribution by taking into account the dependence structure of parameter ω and NDVI, which can provide more accurate probabilistic evaluation of water availability. [ABSTRACT FROM AUTHOR]

The stress stability in plasma-enhanced chemical vapor deposition (PECVD) silicon dioxide (SiO) films is a key factor of device performance. In this study, the PECVD SiO films are annealed at 400-1000 °C in a nitrogen (N) or oxygen (O) ambience for 2 h. The influences of annealing parameters on the stress state and stress stability in PECVD SiO films are investigated. The bonding nature and surface morphology of the films are also studied to analyze the physical mechanism involved. It is demonstrated that the stress stability is first deteriorated and then improved with increasing annealing temperature. In addition, O ambience is more appropriate to improve stress stability than N, and the stress in PECVD SiO film can be stabilized when it is annealed at 1000 °C in O ambience. These results should be able to provide important insights into the design of device fabrication processes. [ABSTRACT FROM AUTHOR]

The Budyko-based elasticity method has been widely employed to clarify the driving factors behind runoff changes. However, different formulations of the Budyko framework could produce biases in the elasticity analysis and the assessment errors induced from different formulations of the Budyko framework in the elasticity method remain unclear. Here, we attempt to address this issue by validating the performance of elasticity methods derived from two analytical Budyko equations (Fu's equation and Choudhury's equation), as well as one empirical Budyko equation (Wang-Tang's equation) of the Budyko framework across 22 basins in China. Validations show that the runoff change simulated by the elasticity method derived from the empirical equation has lower errors compared with the two analytical Budyko equations. Results reveal that in the semi-humid environment, the alteration of basin characteristics takes the main responsibility for the runoff change. However, a clear divergence was found in simulated runoff changes among different Budyko-based elasticity methods in humid basins. For parts of the humid basin, the precipitation is the main driver of runoff change from the analytical Budyko-based elasticity methods, while the alteration of basin characteristics is the main derive of the runoff changes according to based on the empirical Budyko-based elasticity method. This difference could be attributed to the variations in the simulated contributions from the alteration of basin characteristics on runoff changes. Generally, our results highlight the importance of validating different Budyko equations when applying the elasticity method to investigate the driver of the runoff changes in humid regions. • Analytical Budyko-based elasticity methods overestimate runoff changes in wet and dry basins compared to empirical solutions. • A divergence was found from the attribution analysis of runoff change among Budyko-based elasticity methods in humid regions. • This divergence could be attributed to the variations in the effects of the basin characteristics on runoff changes. [ABSTRACT FROM AUTHOR]

• We derived an analytical solution to the impact of seasonal vegetation changes on ET. • Global ET elastic response to seasonal LAI changes has a north-south shift trajectory. • The weak negative ET elastic response to vegetation changes was found under low LAI. Seasonal variation of vegetation profoundly affects the water cycle. However, the seasonal divergence of evapotranspiration (ET) sensitivity in response to vegetation variations has not been fully understood. Here we derived an analytical solution to examine the impact of seasonal vegetation changes on ET with an extended Budyko framework based on an improved ET algorithm with improved water balance constraints. Results reveal a clear seasonal divergence of ET sensitivity to vegetation coverage changes across climate regimes and biomes. Generally, the high ET sensitivity to vegetation coverage has a clear north-south shift trajectory from spring to winter. For moderate-humid regions (0.7 < aridity index < 1.0), vegetation exhibits higher importance in altering ET in March-September. While for moderate-dry regions (1.0 < aridity index < 1.4), the sensitivity of ET to vegetation changes is the highest in September-November. Moreover, the spatial-temporal pattern of ET sensitivity to seasonal vegetation changes is different between short vegetation cover and forest. Additionally, negative ET sensitivity to vegetation coverage changes was discovered in regions with seasonal precipitation of less than 500 mm and sparse vegetation coverage (predominant land cover types of grassland, scrubland, and savannas). In summary, our study provides an analytical solution to estimate ET sensitivity to seasonal vegetation changes within the extended Budyko framework. The results highlight the difference in hydrological response to vegetation dynamics across seasons and vegetation types. [ABSTRACT FROM AUTHOR]

Chinese dark teas (CDTs) are now among the popular tea beverages worldwide due to their unique health benefits. Because the production of CDTs involves fermentation that is characterized by the effect of microbes, microorganisms are believed to play critical roles in the determination of the chemical characteristics of CDTs. Some dominant fungi have been identified from CDTs. In contrast, little, if anything, is known about the composition of bacterial community in CDTs. This study was set to investigate the diversity and variation of bacterial community in four major types of CDTs from China. First, the composition of the bacterial community of CDTs was determined using MiSeq sequencing. From the four typical CDTs, a total of 238 genera that belong to 128 families of bacteria were detected, including most of the families of beneficial bacteria known to be associated with fermented food. While different types of CDTs had generally distinct bacterial structures, the two types of brick teas produced from adjacent regions displayed strong similarity in bacterial composition, suggesting that the producing environment and processing condition perhaps together influence bacterial succession in CDTs. The global characterization of bacterial communities in CDTs is an essential first step for us to understand their function in fermentation and their potential impact on human health. Such knowledge will be important guidance for improving the production of CDTs with higher quality and elevated health benefits. [ABSTRACT FROM AUTHOR]

Accurate estimation of global evapotranspiration (ET) is critical to understand the water and energy cycles in the Earth system. Satellite-driven ET algorithms serve as an effective way to estimate the global ET. However, many algorithms have been designed independently of water balance constraints, which potentially limit their ability to estimate ET in water-limited and high interception regions. As ET remains one of the most uncertain terms in the global water budgets, incorporating water balance constraints into algorithms should improve the performance of ET estimates. In this study, we developed a general solution (denoted PEW) based on the proportionality hypothesis to incorporate available water control into the widely used Priestley Taylor-Jet Propulsion Laboratory (PT-JPL) ET algorithm. Simulated performances of the PEW model and PT-JPL algorithm were evaluated against 106 FLUXNET eddy covariance (EC) towers data at the site scale. Meanwhile, model results were compared at the global scale with the means of the widely used ET products. We found that the PEW model has smaller errors than the original PT-JPL algorithm, with the greatest improvements in water-limited regions and areas characterized by the high interception. Moreover, by incorporating the water balance constraints into the ET algorithm, the PEW model has the ability to distinguish variations in ET affected by El Nino-Southern Oscillation. In summary, our study offers a convincing evidence regarding the incorporation of water balance constraints into remote sensing algorithms for more accurately mapping global terrestrial ET with an enhanced understanding of ET variation under climate change. This model is the first of its kind among remote-sensing models to provide global land ET estimation with the proportionality hypothesis-based water balance constraints. • We develop a new ET algorithm based on proportionality hypothesis and PT-JPL model. • A water balance constraint is introduced to this ET algorithm and applied globally. • The new ET algorithm is validated globally and shows better performance than PT-JPL model. • ET improved most in water-limited regions and areas having a high interception. [ABSTRACT FROM AUTHOR]

• The sea-crossing isolated continuous beam model considering the seabed–pile–seawater–bridge interaction is established using the ADINA software. • The influence of the coupling system on the seismic response of the sea-crossing isolated continuous beam bridge is investigated. • The position of the pile cap effect on the seismic isolation for the continuous beam bridge is compared. To consider the multiple interactions between offshore sites and sea-crossing bridges under seismic actions, a seabed–pile–seawater–bridge interaction model is established by the ADINA software [1]. This study uses seismic fluctuation analysis as an input to bedrock ground motion. It reflects the influence of submarine sites and seawater layers on ground motion characteristics through the fluid-solid coupling of seawater to the seabed. It was found that the whole bridge piers considering the coupling effect are in an elastic state. The yielding of the isolated bearings occurs. Also, the seismic response of the bridge structure under the seabed-pile-seawater-bridge interaction is significantly higher than those under the direct input of the ground motions from the fixed basement assumption. In addition, when the pile cap is above the seabed, the average seismic response of the bridge structure is 1.2–1.3 times the response when the pile cap is below the seabed. Therefore, the seismic design of marine structures should take full account of the influence of the submarine site and the seawater layer. Otherwise, it will result in greater seismic risks for marine structures such as sea-crossing bridges. In addition, this study also suggests the influence of the pile cap location on the seismic response of the bridge. [ABSTRACT FROM AUTHOR]

The stress state of low-pressure chemical vapor deposition (LPCVD) silicon dioxide (SiO 2 ) films fluctuates upon aging due to the ambient moisture. The related variation of the SiO 2 films is a key factor of device reliability. In this study, ion implantation is introduced to improve film stress stability. The stress state modified by ion implantation is discussed in detail and an analytical model is presented. The evolution of the stress in as-deposited and P + -, As + -, and B + -implanted LPCVD SiO 2 films upon aging is investigated, and the bonding nature of the films is also studied to provide insight into the physical mechanisms involved. It is demonstrated that low implantation energy slightly modifies the stress in films. In addition, P + ion is the most appropriate impurity ion to improve film stress stability, and the stress in P + -implanted LPCVD SiO 2 film can be stabilized with a low tensile stress of 67 MPa when the film is implanted at 15 keV with a dose of 1 × 10 15 cm − 2 . [ABSTRACT FROM AUTHOR]

• We presented a self-test method based on the thermopile structural model and electrical characteristics to evaluate the thermal parameters of thermopile IR sensors. • We measured the Seebeck coefficient, thermal conductance, heat capacitance, and thermal time constant of a thermopile IR sensor, respectively. • Compared with the results obtained by other methods, the relative errors are small. • This method could provide certain guiding relevance for associated researchers conducting design improvement and performance testing because of its simplicity and effectiveness. Thermopile infrared (IR) sensors are thermal-type sensors. It is of great significance to evaluate its four thermal parameters: Seebeck coefficient, thermal conductance, heat capacitance, and thermal time constant. In this work, an effective self-test method to measure these thermal parameters is proposed that takes advantages of thermopile IR sensors' structural and electrical characteristics and does not need to add heater in structure. The technique to accurately extract thermal parameters is analyzed carefully, and its validity is verified by a thermopile IR sensor. The experimental Seebeck coefficient is consistent with the tested value of on-chip test structure in the same die, and the experimental thermal conductance, heat capacitance, and thermal time constant results agree well with the theoretical analysis of structure. These demonstrate that this method is effective and accurate, as well as simple for researchers to apply. [ABSTRACT FROM AUTHOR]

In this paper, a typical mobile communication environment is assumed and the eigenvalue distributions of the correlation matrix of a MIMO channel with the spatial correlation of the multipath taken into account are studied by simulation. Based on this study, a simple method is proposed for accurately deriving the probability distribu- tion of the largest eigenvalue of the correlation matrix. The proposed approximation equation is compared with simu- lation results and good agreement is obtained. In order to understand the information transmission capability of MIMO in a multipath fading environment with spatial correlation, the proposed equation is used for studying the effect of the spatial correlation on channel capacity. Finally, the digital transmission characteristics (relationship be- tween the BER and the CNR) with correlation taken into account are obtained. [ABSTRACT FROM AUTHOR]

• An electrical method is proposed to measure thermal parameters by self-heating effect. • The theory and technique to accurately extract thermal parameters is analyzed. • The validity is verified by an IR FPA and consistent with the theoretical analysis. Diode-based thermal sensors have a wide range of applications in industry and civil. Thermal conductance, heat capacity and thermal time constant are three main thermal parameters of diode-based thermal sensors. Extracting their thermal parameters is of great importance in evaluating sensors' performance. In this work, an effective electrical circuit is developed to determine these thermal parameters of diode-based thermal sensors. The method takes advantage of self-heating effect of sensors and involves the measurement of time dependent forward voltage drop of sensors under a square-pulse voltage. The technique to accurately extract thermal parameters from the circuit is analyzed carefully, and its validity is verified experimentally using an infrared focal plane array with series diodes. The experimental results are in good agreement with the theoretical analyses of structure. The measurement technology is very easy for engineers to grasp. [ABSTRACT FROM AUTHOR]

Insect‐induced plant volatile organic compounds (VOCs) may function as either direct defence molecules to deter insects or indirect defence signals to attract the natural enemies of the invading insects. Tea (Camellia sinensis L.), an important leaf‐based beverage crop, is mainly infested by Ectropis obliqua which causes the most serious damage. Here, we report a mechanistic investigation of tea plant‐derived VOCs in an indirect defence mechanism against E. obliqua. Parasitoid wasp Parapanteles hyposidrae, a natural enemy of E. obliqua, showed strong electrophysiological response and selection behaviour towards S‐linalool and β‐ocimene, two monoterpenes with elevated emission from E. obliqua‐damaged tea plants. Larvae frass of E. obliqua, which also released S‐linalool and β‐ocimene, was found to attract both mated female or male Pa. hyposidrae according to gas chromatography‐electroantennogram detection and Y‐tube olfactometer assays. In a field setting, both S‐linalool and β‐ocimene were effective in recruiting both female and male Pa. hyposidrae wasps. To understand the molecular mechanism of monoterpenes‐mediated indirect defence in tea plants, two novel monoterpene synthase genes, CsLIS and CsOCS‐SCZ, involved in the biosynthesis of S‐linalool or β‐ocimene, respectively, were identified and biochemically characterised. When the expression of these two genes in tea plants was inhibited by antisense oligodeoxynucleotide, both volatile emission and attraction of wasps were reduced. Furthermore, gene expression analysis suggested that the expression of CsLIS and CsOCS‐SCZ is regulated by the jasmonic acid signalling pathway in the tea plant. Summary statement: S‐linalool and β‐ocimene elevated emission from Ectropis obliqua‐damaged tea plants. The two monoterpenes were key chemical cues, aroused parasitoid wasp Parapanteles hyposidrae, a dominant natural enemy of E. obliqua, strong electrophysiological response, selection behaviour, and aggregated the wasp in the field. Two novel Terpene synthases CsLIS and CsOCS‐SCZ, involved in the biosynthesis of S‐linalool and β‐ocimene were identified, when they were inhibited in tea plants by antisense oligonucleotides, both volatile emission and attraction of wasps were reduced. [ABSTRACT FROM AUTHOR]

Micro-Pirani vacuum sensors usually operate at hundreds of microwatts, which limits their application in battery-powered sensor systems. This paper reports a diode-based, low power consumption micro-Pirani vacuum sensor that has high sensitivity. Optimizations to the micro-Pirani vacuum sensor were made regarding two aspects. On the one hand, a greater temperature coefficient was obtained without increasing power consumption by taking advantage of series diodes; on the other hand, the sensor structure and geometries were redesigned to enlarge temperature variation. After that, the sensor was fabricated and tested. Test results indicated that the dynamic vacuum pressure range of the sensor was from 10−1 to 104 Pa when the forward bias current was as low as 10 μA with a power consumption of 50 μW. Average sensitivity was up to 90 μV/Pa and the sensitivity of unit power consumption increased to 1.8 V/W/Pa. In addition, the sensor could also work at a greater forward bias current for better sensor performance. [ABSTRACT FROM AUTHOR]

Background: Three species of wintersweets: Chimonanthus salicifolius S. Y. Hu, Chimonanthus zhejiangensis M. C. Liu and Chimonanthus grammalus M. C. Liu are widely distributed in China. The three wintersweets belonging to the genus of Chimonanthus that can synthesize abundant terpenoids that are beneficial to human health. Their buds and leaves are traditional Chinese herb applied by the 'She' ethnic minority in southeast of China. Squalene is a multi-functional and ubiquitous triterpene in plants, which is biosynthesized by squalene synthase (SQS) using farnesyl diphosphate (FPP) as the substrate. The synthesis of squalene in wintersweet was not clearly. This work would provide us much help to further understand the terpene metabolism in wintersweet and its health function to people at phytochemistry and molecular levels.Results: In this study, we identified squalene component in the extractions of leaves of three wintersweets and isolated SQS genes from leaf transcriptomes. The three SQSs were highly conservative, so CzSQS from C. zhejiangensis was just determined the enzymatic activity. The in vitro expressed CzSQS that deleted two transmembrane domains could catalyze FPP to generate squalene with the presence of NADPH and Mg2+.Conclusions: The squalene was one of wintersweet leaves phytochemicals. The squalene synthases of three wintersweet plants were highly conserved. The CzSQS was capable to catalyze two FPP molecules to squalene. [ABSTRACT FROM AUTHOR]

Terpenes and their derivatives are vital components of tea aroma. Their constitution and quantity are highly important criteria for the sensory evaluation of teas. Biologically, terpenes are involved in chemical resistance of tea plant against biotic and/or abiotic stresses. The goal of this study is to identify volatile terpenes of tea plants implicated in defense against herbivores and to identify terpene synthase (TPS) genes for their biosynthesis. Upon herbivory by tea geometrid (Ectropis obliqua Prout), tea plants were found to emit two sesquiterpenes, (E , E)-α-farnesene and (E)-nerolidol, which were undetectable in intact tea plants. The induced emission of (E , E)-α-farnesene and (E)-nerolidol suggests that they function in either direct or indirect defense of tea plants against the tea geometrid. Candidate TPS genes were identified from the transcriptomes of tea plants infested by tea geometrids. Two dedicated sesquiterpene synthases, Cs AFR and Cs NES2, were identified. Cs AFR belongs to the TPS-b clade and can catalyze the formation of (E , E)-α-farnesene from (E , E)-FPP. Cs NES2 belongs to the TPS-g clade and can synthesize (E)-nerolidol using (E , E)-FPP. The two genes were also both dramatically upregulated by herbivore damage. In summary, we showed that two novel sesquiterpene synthase genes CsAFR and CsNSE2 are inducible by herbivory and responsible for the elevated emission of herbivore-induced (E , E)-α-farnesene and (E)-nerolidol, which are implicated in tea plant defense against herbivores. • Identified two sesquiterpene synthase genes that are dedicated for the biosynthesis of (E , E)-α-farnesene and (E)-nerolidol, respectively. • The two genes can be induced by herbivore damages and emitted the products (E , E)-α-farnesene and (E)-nerolidol. • CsAFR and CsNSE2 are implicated in volatile-mediated defense of tea plants against herbivores. [ABSTRACT FROM AUTHOR]

X-ray free electron laser (XFEL) requires operation of an advanced silicon pixel sensor (SPS) under ultra-high voltage for detection of fast electron–hole pairs. In this study, a high-voltage tolerant SPS is designed and fabricated by considering suppressing the soft-breakdown of the current collection ring (CCR) and increasing the breakdown voltage of the pixel array after dicing the sensor. It is found that a soft-breakdown behavior of CCR in one diced SPS occurred before a hard breakdown happening in the pixel and it may cause the degradation of maximum hard breakdown voltage in pixel region, which, in particular, turns worse as the increasing of the number of guard rings. An optimized method with the expansion of the non-sensitive area is used to effectively prevent the occurrence of soft-breakdown and increase the operation voltage of the SPS. Ultimately, a high performance SPS with a maximum breakdown voltage exceeding 1000 V and reversed leakage of ∼ 1.5 pA per pixel at bias 500 V is obtained. Together with the optimized multi-guard ring structure, a record ultra-high avalanche breakdown voltage of over 2100 V is obtained, which provides a promising approach to develop ultra-fast detector in an XFEL. [ABSTRACT FROM AUTHOR]

The frequency of large-scale anomalous precipitation events over China has increased during 1961–2018. However, it remains challenging to understand the mechanisms associated with these anomalous events showing different spatial patterns. Here, we applied an autoencoder technique to identify large-scale anomalous precipitation events for both observations and model simulations, which were then classified into several patterns through a self-organizing map method. The synoptic behavior and atmospheric circulation background of different anomalous patterns were also analyzed using simultaneous composite analyses. Results show that occurrences of different anomalous precipitation patterns have increased significantly, except those centered in North China, Northeast China, and the Yangtze River basin. The anomalous precipitation patterns manifest various intraseasonal distributions, which are linked to zonal oscillations of the western North Pacific subtropical high (WNPSH) and meridional displacements of East Asia westerly jet (EAJ). Accompanied by the westward movement of WNPSH, anticyclonic systems transport warm moist air from the Indian Ocean and the South China Sea to converge with the cold air caused by anomalous cyclones over the northwest flank of the WNPSH, leading to large-scale anomalous precipitation in these regions. Besides WNPSH, the northward and southward displacements of EAJ also favor the occurrence of anomalous precipitation events in northern and southern China, respectively. Our study also illustrates that the occurrence frequency of anomalous precipitation events is projected to increase remarkably under the Shared Socioeconomic Pathway 5–8.5 (SSP585) scenario by rates of twofold to fourfold. [ABSTRACT FROM AUTHOR]

Representing atmospheric evaporating capability for a hypothetical reference surface, potential evapotranspiration (PET) determines the upper limit of actual evapotranspiration and is an important input to hydrological models. Due that present climate models do not give direct estimates of PET when simulating the hydrological response to future climate change, the PET must be estimated first and is subject to the uncertainty on account of many existing formulae and different input data reliabilities. Using four different PET estimation approaches, i.e., the more physically Penman (PN) equation with less reliable input variables, more empirical radiation-based Priestley-Taylor (PT) equation with relatively dependable downscaled data, the most simply temperature-based Hamon (HM) equation with the most reliable downscaled variable, and downscaling PET directly by the statistical downscaling model, this paper investigated the differences of runoff projection caused by the alternative PET methods by a well calibrated abcd monthly hydrological model. Three catchments, i.e., the Luanhe River Basin, the Source Region of the Yellow River and the Ganjiang River Basin, representing a large climatic diversity were chosen as examples to illustrate this issue. The results indicated that although similar monthly patterns of PET over the period 2021–2050 for each catchment were provided by the four methods, the magnitudes of PET were still slightly different, especially for spring and summer months in the Luanhe River Basin and the Source Region of the Yellow River with relatively dry climate feature. The apparent discrepancy in magnitude of change in future runoff and even the diverse change direction for summer months in the Luanhe River Basin and spring months in the Source Region of the Yellow River indicated that the PET method related uncertainty occurred, especially in the Luanhe River Basin and the Source Region of the Yellow River with smaller aridity index. Moreover, the possible reason of discrepancies in uncertainty between three catchments was quantitatively discussed by the contribution analysis based on climatic elasticity method. This study can provide beneficial reference to comprehensively understand the impacts of climate change on hydrological regime and thus improve the regional strategy for future water resource management. [ABSTRACT FROM AUTHOR]

Soil fungi are key drivers regulating processes between ecosystem fertility and plant growth; however, the responses of soil fungi community composition and diversity in deeper soil layers to the plantation and fertilization remain limited. Using soil samples along with vertical soil profile gradients with 0–10 cm, 0–20 cm, 20–40 cm, and 40–60 cm in a tea garden, we used Illumina sequencing to investigate the fungal diversity and assemblage complexity, and correlated to the low, middle, and high-level fertilize levels. The results showed that the fungal community dissimilarities were different between adjacent forests and tea gardens, with predominate groups changed from saprotrophs to symbiotrophs and pathotrophs after the forest converted to the tea garden. Additionally, the symbiotrophs were more sensitive to soil fertility than pathotrophs and saprotrophs. Subsoil fungal communities present lower diversity and fewer network connections under high soil fertility, which contrasted with the trends of topsoil fungi. Soil pH and nutrients were correlated with fungal diversity in the topsoils, while soil K and P concentrations showed significant effects in the subsoil. Overall, the soil fungal communities in tea gardens responded to soil fertility varied with soil vertical spatial locations, which can be explained by the vertical distribution of fungal species. It was revealed that fertility treatment could affect fungal diversity, and alter network structure and potential ecosystem function in tea garden subsoils. [ABSTRACT FROM AUTHOR]

Simple Summary: Tritrophic interactions have achieved much attention in research on ecology. The tea plant Camellia sinensis (L.) O. Kuntze is a major economic crop in Asian countries, especially in China. Tea plants suffer infestations from herbivory attack during their lifetime. The tea green leafhopper (Empoasca onukii Matsuda) is a major pest for tea plants. The parasitic or predatory natural enemies of tea green leafhoppers (TGLs) can feed on their eggs, nymphs, or adults. However, a detailed mathematical model for tea plants–TGLs–natural enemies is still lacking. In the current work, we established a novel model based on laboratory measurements or field observations with temperature-dependent effects on tritrophic interactions for tea ecosystems. As expected, cyclic behaviors are identified. Stochastic simulations further showed two TGL outbreaks, the timing of which is consistent with field observations. Effective accumulated temperature (EAT) is possibly an important predictor of TGL outbreak. Applying slow-releasing semiochemicals as either repellents or attractants may be highly efficacious for pest biocontrol. An optimal treatment time of semiochemicals can also be determined. Our detailed model identifies key features of tritrophic interactions involving tea plants and can be extended to other ecosystems. The tea green leaf hopper, Empoasca onukii Matsuda, is a severe pest of tea plants. Volatile emissions from tea shoots infested by the tea green leafhopper may directly repel insect feeding or attract natural enemies. Many studies have been conducted on various aspects of the tritrophic relationship involving tea plants, tea green leafhoppers and natural enemies. However, mathematic models which could explain the dynamic mechanisms of this tritrophic interaction are still lacking. In the current work, we constructed a realistic and stochastic model with temperature-dependent features to characterize the tritrophic interactions in the tea agroecosystem. Model outputs showed that two leafhopper outbreaks occur in a year, with their features being consistent with field observations. Simulations showed that daily average effective accumulated temperature (EAT) might be an important metric for outbreak prediction. We also showed that application of slow-releasing semiochemicals, as either repellents or attractants, may be highly efficacious for pest biocontrol and can significantly increase tea yields. Furthermore, the start date of applying semiochemicals can be optimized to effectively increase tea yields. The current model qualitatively characterizes key features of the tritrophic interactions and provides critical insight into pest control in tea ecosystems. [ABSTRACT FROM AUTHOR]

[Display omitted] • AAs and flavonoids contrasting accumulated in LJ43 and QT at different altitudes. • Differences in primary metabolites influenced by cultivar and altitude were identified. • Theanine, glutamic acid, EGCG, EGC, and saccharides showed strong correlations. • Maintain of AAs, flavonoids and saccharides contributed to umami at high-altitude green tea. • Derivates of flavonoid, saccharides, and AAs increased sweet aftertaste in low-altitude black tea. Variations in cultivars and cultivation altitudes have significant impacts on tea flavour compounds however lack of comprehensive understanding. This study provided insights into differential accumulation of crucial flavour compounds in response to cultivars, cultivation altitudes, and processing. Twelve flavonoids (262.4 ∼ 275.4 mg•g−1) and 20 amino acids (AAs) (56.5 ∼ 64.8 mg•g−1) were comparative analyzed in 'Longjing 43′ and 'Qunti' fresh leaves harvested at low (80 m, LA) and high (500 m, HA) altitudes. Additionally, an in-depth correlation unravelling of 31 alkaloids, 25 fatty acids, 31 saccharides, 8 organic acids, and 7 vitamins and flavonoids/AAs during green tea (GT) and black tea (BT) processing was performed. Enhenced flavonoid accumulation alongside higher AAs and saccharides in HA GT promoted a sweet/mellow flavour. Abundant flavonoids, AAs, and saccharides derivates in LA BT gave rise to a sweet aftertaste. The study presents an integrated illustration of major flavour compounds' differential accumulation patterns and their interrelations, providing new insights into the influence of cultivation conditions on tea flavour. [ABSTRACT FROM AUTHOR]

[Display omitted] • Flavonoids decreased from > 240 mg·g−1 to < 30 mg·g−1 promised colour & taste. • Withering dehydration primed carotenes and xanthophylls accumulated. • 49 VIP > 1 PMs were explored correlations with carotenoids, flavonoids, and volatiles. • Maillard reaction products accumulated in BT offered sweet and caramel flavour. • β-Carotene, α-linolenic acid, and Phe contributed as floral/sweet aroma precursors. Intelligently processed black teas (BT) possess premium quality but there is a lack in comprehensive understanding of flavor formation mechanism. In this study, the accumulation of carotenoids, flavonoids, and Maillard products and (non)enzymatic degradations and conjugations to characterized flavors were comprehensively studied. Significant decrease was observed that flava-3-ols were heavily oxidised from > 240 mg·g−1 in fresh leaves (FL) to < 30 mg·g−1, while other 21 flavonoids decreased by < 30% in BT, accompanied by a sweet aftertaste. Carotenes and xanthophylls, significantly accumulated during withering compared to FL (from 641 ± 39.7 μg·g−1 to 728 ± 44.9 μg·g−1) but decreased in BT. Strong correlations were confirmed between the 218 primary metabolites, carotenoids, and flavonoids, and their contributions to BT sweet tastes were elucidated. Furthermore, 45 floral/sweet volatiles with VIP > 1 originating from carotenoids, lipids, and amino acids were screened. An integrated illustration of pigments thermal- and enzymatic-dominated contributions to BT flavour was comprehensively conducted. [ABSTRACT FROM AUTHOR]

Compound Drought and Saltwater intrusion Events (CDSEs) refer to hydrologic drought and saltwater intrusion occurring simultaneously or consecutively in estuaries, and exacerbate the negative impacts resulting from an individual extreme event. CDSEs have been drawing increasing attention due to their potential adverse impacts on water resources, crop production, and food security. A new Standardized compound Drought and Saltwater intrusion Index (SDSI) was developed in this study to systematically detect changes in the severity of CDSEs in six estuaries (Little Back, Ebro, Rhine, Orange, Pearl River and Murray). The results illustrated that (1) compared to the Standardized Runoff Index (SRI), SDSI effectively characterizes and quantifies the occurrences and severity of CDSEs in major river estuaries worldwide. (2) Temporally, the SDSI trend varied across estuaries. Specifically, a decreasing trend was observed in the Little Back, Ebro, and Orange estuaries, with corresponding Zs values of −2.43, −3.63, and −3.23. (3) Spatially, moderate CDSEs occurred more frequently among different estuaries, and their frequency, duration and severity varied in different estuaries. Notably, Ebro, Rhine and Murray River estuaries had the highest probability of CDSEs, nearing 60%. Among them, the Murray Estuary had the longest average duration, spanning 7.68 months, and the highest severity was 5.94. (4) According to the contributions analysis, saltwater intrusion plays a dominant role in influencing SDSI severity, accounting for a substantial percentage (54%–95.30%) compared to runoff. Notably, the Orange Estuary experienced the greatest impact from saltwater intrusion (81.54%–95.30%), while the Murray Estuary had relatively equal contributions from hydrological drought and saltwater intrusion. • The simultaneous occurrence of hydrological droughts and saltwater intrusion is considered. • The Little Back, Ebro and Orange estuaries exhibit a significant decreasing trend in SDSI. • Moderate compound drought and saltwater intrusion events occurred more frequently among different estuaries. [ABSTRACT FROM AUTHOR]

[Display omitted] • Flavonols, glutamic acid, and glutamine promised sweet aftertaste and umami in GT. • >200 PMs were explored of their strongly corelations with GT flavor contribution. • Non-enzymatic degradation of carotenoids and lipids contributed floral/green aroma. • Accumulation of Maillard products improved sweet and roasted flavor in SGT/NGT. • Integrated pigment alterations and associated flavor development were illustrated. Strip/needle green teas (SGT/NGT) processed using innovative technologies are in high demand; however, mechanisms behind their color and flavor have not been comprehensively studied. We aimed to reveal the dynamics of major pigmented components (carotenoids, lipids, flavonoids, and Maillard products) and their contributions to the flavor of green teas. The total content of flavonoids in SGT and NGT were 255 ± 4.51 and 201 ± 3.91 mg·g−1, respectively; these values are slightly lower than that in fresh leaves (FLs), resulting in a fresh and sweet aftertaste. In average, carotene content in SGT/NGT (24.8 μg·g−1) was higher than in FL (17.4 μg·g−1), whilst xanthophyll content (603 μg·g−1) decreased to one-half of that in FL (310 μg·g−1). Among the 218 primary metabolites, glutamine, glutamic acid, and arginine were found to accumulate and were dominate contributors for the umami and sweet taste. Notably, more than 96 volatiles were screened and revealed their correlations with carotenoids, lipids, and amino acids. Overall, the synergism between pigments and their non-enzymatic derivates' contribution to GT characterized flavor was illustrated. [ABSTRACT FROM AUTHOR]

Background: Shoot branching is one of the important agronomic traits affecting yields and quality of tea plant (Camellia sinensis). Cytokinins (CTKs) play critical roles in regulating shoot branching. However, whether and how differently alternative splicing (AS) variant of CTKs-related genes can influence shoot branching of tea plant is still not fully elucidated. Results: In this study, five AS variants of CTK biosynthetic gene adenylate isopentenyltransferase (CsA-IPT5) with different 3′ untranslated region (3ˊ UTR) and 5ˊ UTR from tea plant were cloned and investigated for their regulatory effects. Transient expression assays showed that there were significant negative correlations between CsA-IPT5 protein expression, mRNA expression of CsA-IPT5 AS variants and the number of ATTTA motifs, respectively. Shoot branching processes induced by exogenous 6-BA or pruning were studied, where CsA-IPT5 was demonstrated to regulate protein synthesis of CsA-IPT5, as well as the biosynthesis of trans-zeatin (tZ)- and isopentenyladenine (iP)-CTKs, through transcriptionally changing ratios of its five AS variants in these processes. Furthermore, the 3′ UTR AS variant 2 (3AS2) might act as the predominant AS transcript. Conclusions: Together, our results indicate that 3AS2 of the CsA-IPT5 gene is potential in regulating shoot branching of tea plant and provides a gene resource for improving the plant-type of woody plants. [ABSTRACT FROM AUTHOR]

Wintersweet (Chimonanthus praecox), a classical winter-blooming magnoliids species with great aesthetic value highlighting the on the brilliant yellow flower and pleasant floral aroma, possesses diverse varieties mainly classified in three groups (Concolor, Patens, and Rubrum group) with the most striking variation in the tepal color. The recent release of the genome in two wintersweet varieties belonging to Patens and Rubrum group successfully elucidated the molecular mechanisms underlying some ornamental traits highlighting the flowering time, floral scent and tepal color. In this study, the chromosome-scale genome of C. praecox var. concolor was assembled to further verify the placement of magnoliids and exploit the genetic variation underscoring the diverse flowering traits among different wintersweet groups. Phylogenomic analyses placed magnoliids including C. praecox var. concolor as the sister to eudicots. The C. praecox var. concolor 's genome experienced two rounds of whole genome duplication (WGD). Multiple gene families involved in floral development including ANR1 and PI genes were retained and expanded during these WGD events. The expansion and expression pattern of SVP and FUL genes suggest their pivotal role in unique character of winter-flowering. With the pleasant fragrance as the aesthetic characteristics, linalool and benzyl acetate were identified as the top abundant constituents in the floral scent of Concolor wintersweet. Integrating metabolic, genomic, and transcriptomic analyses with enzyme assays led to the identification of CpTPS3 (CpLIS) and CpBAHD2 (CpBEAT), which are responsible for the biosynthesis of linalool and benzyl acetate, respectively, in the Concolor variety. Taken together, the assembled genome of C. praecox var. concolor enables the comparative analysis of the genetic basis underlying both conserved and variable floral traits and provides a useful foundation for variety improvements by molecular breeding in wintersweet. • A high-quality chromosome-level genome of Concolor wintersweet was assembled. • Phylogenomic analyses placed magnoliids as the sister to eudicots. • CpSVP and CpFUL genes are the key regulators in controlling the unique winter-flowering of Concolor wintersweet. • CpTPS3\CpBEAT were functionally identified to produce linalool and benzyl acetate as floral volatiles in Concolor wintersweet. • Comparative analysis highlights the genetic basis in conserved and varied floral traits among three wintersweet varieties. [ABSTRACT FROM AUTHOR]

Reference evapotranspiration (ET0), which is an indicator of atmospheric evaporation demand over a hypothetical reference surface, is expected to alter along with global climate change. In this study, the changes and driving forces of historical ET0 and its future projections in Xinjiang, China, were comprehensively conducted. The trend analysis revealed that regional ET0 decreased significantly at a rate of −4.1 mm/year2 during 1961–1993 and increased at a rate of 3.4 mm/year2 during 1994–2010. To explore the possible causes, the contributions of major climatic variables to the ET0 trends were derived based on the differential equation method. During 1961–1993, the decreasing trend of ET0 was primarily ascribed to the wind speed. The integrated negative effect from the decrease in wind speed (U) and increase in relative humidity (RH) was more significant than the positive effect from the increase in air temperature (T), resulting in the decrease in ET0. During 1994–2010, combined with increasing T and decreasing RH, the increase in U offset the effect of the net radiation (Rn) decrease and led to an increase in ET0. Future ET0 projections over three periods (2010–2039, 2040–2069, and 2070–2099, which are named as 2020s, 2050s, and 2080s, respectively) were conducted based on the general circulation models under two representative concentration pathways scenarios (RCP4.5 and RCP8.5). A continuous increasing trend in ET0 was demonstrated in the 21st century. The increase in ET0 will increase the irrigated water resource consumption and bring new challenge to water resource management in this area. [ABSTRACT FROM AUTHOR]

Summary: Rice blast disease, caused by the fungus Magnaporthe oryzae, is the most devastating disease of rice. In our ongoing characterization of the defence mechanisms of rice plants against M. oryzae, a terpene synthase gene OsTPS19 was identified as a candidate defence gene. Here, we report the functional characterization of OsTPS19, which is up‐regulated by M. oryzae infection. Overexpression of OsTPS19 in rice plants enhanced resistance against M. oryzae, while OsTPS19 RNAi lines were more susceptible to the pathogen. Metabolic analysis revealed that the production of a monoterpene (S)‐limonene was increased and decreased in OsTPS19 overexpression and RNAi lines, respectively, suggesting that OsTPS19 functions as a limonene synthase in planta. This notion was further supported by in vitro enzyme assays with recombinant OsTPS19, in which OsTPS19 had both sesquiterpene activity and monoterpene synthase activity, with limonene as a major product. Furthermore, in a subcellular localization experiment, OsTPS19 was localized in plastids. OsTPS19 has a highly homologous paralog, OsTPS20, which likely resulted from a recent gene duplication event. We found that the variation in OsTPS19 and OsTPS20 enzyme activities was determined by a single amino acid in the active site cavity. The expression of OsTPS20 was not affected by M. oryzae infection. This indicates functional divergence of OsTPS19 and OsTPS20. Lastly, (S)‐limonene inhibited the germination of M. oryzae spores in vitro. OsTPS19 was determined to function as an (S)‐limonene synthase in rice and plays a role in defence against M. oryzae, at least partly, by inhibiting spore germination. [ABSTRACT FROM AUTHOR]

It has become increasingly important to quantify carbon and water fluxes due to their roles in global warming and climate change, particularly for the agroecosystems. However, the dynamics of carbon and water fluxes have not been clearly recognized in rotation croplands with complex and changeable climate. Here, the variations of net ecosystem productivity (NEP), evapotranspiration (ET) and the water use efficiency (WUE, defined as NEP/ET), and their responses to the environmental factors were investigated in a wheat-maize rotation cropland across the Huaibei Plain of China over 2013–2015. The total average NEP, ET and average WUE respectively were 489.1 gC m-2, 315.8 kgH 2 O m-2, 4.4 gC kg-1H 2 O for wheat and 192.5 gC m-2, 249.0 kgH 2 O m-2, 3.6 gC kg-1H 2 O for maize, implying that wheat season sequestered more CO 2 than maize season. Spring drought and summer flood affected WUE of wheat and maize, respectively. Daily wheat WUE seemed to be more sensitive to changes in photosynthetically active radiation (PAR), vapor pressure deficit (VPD), soil water content (SWC) and canopy conductance (G c). PAR was the dominant factor controlling diurnal dynamics of NEP and ET, while the opposite effect of VPD on NEP was recognized. NEP increasing with PAR was limited by high VPD, which obviously when VPD exceeded 2 kPa during the maize season. Maize NEP was limited with VPD under high solar radiation (> 500 μmol m-2 s-1). WUEs of wheat and maize were negatively related to SWC and G c , and the sensitivity of WUE response to SWC and G c increased with the increase of PAR or VPD range. Sub-diurnal NEP against PAR, VPD or temperature showed clockwise hysteresis but ET against PAR or windspeed showed counter-clockwise hysteresis, and these hystereses were mainly caused by the interplay between evaporative demand and moisture supply, photosynthesis and carbon allocation of the agroecosystems. [Display omitted] • The wheat season sequestered more CO2 than the maize season. • Spring drought and summer flood affected WUE of wheat and maize, respectively. • Wheat WUE seemed to be more sensitive to changes in environmental factors. • PAR was the dominant factor controlling diurnal dynamics of NEP and ET. [ABSTRACT FROM AUTHOR]

• Biochar addition increased the tea root biomass, nutrient uptake and soil nutrients contents. • Biochar application promoted tea root growth by increasing soil nutrient contents. • Biochar with homogenized application method was the optimal choice on tea plant growth and soil fertility. Although the application of biochar increases crop productivity and soil fertility, the effects of different biochar application methods on tea plant growth and soil nutrient status remain unclear. In this study, we conducted a root chamber experiment to assess the effects of various biochar application methods on root growth in tea plants and edaphic factors. Four treatments were included: T1) No biochar, T2) Homogenized biochar, T3) Localized biochar, and T4) Strip biochar. Biochar application generally resulted in higher macronutrient contents in tea plants, with 114–371%, 196–1167%, and 327–960% increases in nitrogen (N), phosphorus (P), and potassium (K), respectively. Biochar application also increased the soil pH by 18.7–22.5% compared to the control. T2 treatment increased the leaf and root biomasses by 80.9% and 262.2%, respectively, compared to the control, and the total carbon and soil nutrient [i.e., total N, inorganic N, available P, and available K, calcium (Ca), and magnesium (Mg)] contents were significantly higher than in the control. Variation in root growth was significantly explained by soil properties, including microbial biomass carbon, Ca, Mg, and total N (P < 0.05), with contributions of 47.9%, 15.6%, 17.6%, and 4.7%, respectively. These results suggest that biochar application in acidic soils would increase tea plant productivity and soil nutrient contents. Overall, homogenized biochar application led to optimal tea plant growth and soil fertility. [Display omitted] [ABSTRACT FROM AUTHOR]

Carotenoids differentiate among tea cultivars and play role in contributing aroma flavor and colour appearance in tea products. In this study, 3 carotenes and 16 xanthophylls were accurately quantified of 0.79–1.56 × 103 μg g−1 in 15 tea cultivars possessing leaves of different colours. Lutein and β-carotene accounted for >80% of total carotenoids. Single carotenoid accumulation patterns and their correlations with chlorophylls and primary metabolites (amino acids, alkaloids, and saccharides) were elucidated. Tea processing (withering, 'kill-green,' fermentation, and drying processes) decreased tea carotenoids by >65%, promoting volatile apocarotenoid production. In total, 25 crucial carotenoid-derived aroma compounds were detected in green, white, and black teas prepared from purple shoots. Additionally, α/β-ionone and their derivates, and dihydroactinidiolide accounted for >50% of total volatiles and therefore explained the fruity aroma in purple tea products. A comprehensive integrative analysis of sensory attributes and volatile and carotenoid precursor dynamics clearly revealed patterns of tea carotenoid accumulation and degradation contribution to tea aroma. [Display omitted] • Lipid-soluble pigments in green-, yellow-, and purple-leaf teas were compared. • Carotenoid and chlorophyll correlations in purple-coloured leaves were unraveled. • Strong connection among primary metabolites and lutein accumulation were confirmed. • Carotenoid-derived aroma in tea products prepared from purple leaves were analysed. [ABSTRACT FROM AUTHOR]

Future changes in reference evapotranspiration (ET0) are of increasing importance in assessing the potential impacts on hydrology and water resources systems of more pronounced climate change. This study assesses the applicability of the Statistical Downscaling Model (SDSM) in projecting ET0, and investigates the seasonal and spatial patterns of future ET0 based on general circulation models (GCMs) across the Haihe River Basin. The results indicate that SDSM can downscale ET0 well in term of different basin-averaged measures for the HadCM3 and CGCM3 GCMs. HadCM3 has a much superior capability in capturing inter-annual variability compared to CGCM3 and thus is chosen as the sole model to assess the changes in future ET0. There are three homogeneous sub-regions of the Haihe River Basin: Northwest, Northeast and Southeast. Change points are detected at around 2050 and 2080 under the A2 and B2 scenarios, respectively. The Northwest is revealed to have a slight to strong increase in ET0, while the Northeast and the Southeast tend to experience a pattern change from decrease to increase in ET0. EDITOR M.C. Acreman ASSOCIATE EDITOR J. Thompson [ABSTRACT FROM AUTHOR]

The use of biochar has increased, as its physicochemical properties reduce the adverse effects of pesticides. However, few studies have comprehensively investigated the effects of biochar on the distribution of pesticides in a plant–soil–groundwater system. In this study, a biochar produced from rice straw at 550 °C was chosen, and column experiments with five rated of biochar application (application rates = 0.0, 1.0, 2.0, 3.0, and 4.0% w/w for B0–B4, respectively) were conducted to investigate the capacity of biochar to immobilize imidacloprid (IMI) in soil, thereby decreasing its uptake by plants and leaching from soil into groundwater. Our results showed that IMI in plants, leached from soil, and detected in soil accounted for 3.78, 1.76, and 36.4% of the total IMI input, respectively, and the biochar treatments dramatically decreased the IMI distribution to 0.57, 0.11, and 13.4%, respectively. By contrast, the percentage of undetected IMI increased from 58.1% in the B0 treatment to an average of 86.0% in the biochar treatments. Biochar treatments increased IMI immobilization in soil, which could be related to the increased soil carbon content, surface area, cation exchange capacity. This study indicates that biochar with characters of high surface area and porosity can stabilize IMI and reduce its potential to harm plants and groundwater. [Display omitted] • The biochar treatments on the distribution of IMI in a plant–soil–groundwater system were analyzed. • Biochar reduced IMI accumulation in plants. • Biochar decreased the amount of IMI leaching out of soil. • Biochar increased the immobilization of IMI. [ABSTRACT FROM AUTHOR]

Biochar is widely used in agriculture to improve soil fertility and plant growth. However, a comprehensive assessment of how biochar amendment affects plant root growth is lacking. This study investigated the change in plant root biomass in response to biochar application, including impact factors such as the biochar feedstock and application rate, plant type, and soil pH. The Science Direct, Web Of Science, and Scopus databases were employed to search for literature published before 2021. The published papers with at least three replicates of biochar-amended treatments and a control at the same site were selected for meta-analysis. Our results showed that 165 (81.3%) of 203 datasets from 47 published studies indicated positive effects of biochar amendment on root growth with a mean relative increase of 32%. The feedstocks of biochar and its rate of application were the main factors that determined its effects on plant root growth. The increment of root biomass following biochar amendment was the greatest for trees (+101.6%), followed by grasses (+66.0%), vegetables (+26.9%), and cereals (+12.7%). The positive effects mainly depended on feedstock sources, with the highest positive effect (+46.2%) for gramineous, followed by woody plants (+25.8%) and green wastes (+21.1%). Linear regression analysis and SEM (Structural equation modeling) analysis showed that total nitrogen (TN) and available phosphorus (AK) are one of the most important factors affecting the increase of root biomass. These results suggest that biochar can be considered an effective amendment to improve root growth and soil fertility. Biochar feedstock sources, application rates, and plant types should be considered to assess the potential benefits of biochar for root growth and soil quality. [ABSTRACT FROM AUTHOR]